'I don't care': Bourke St accused’s crazy comet theory

A MAN accused of killing six pedestrians in Melbourne's Bourke Street is not bothered if he is found fit to plead because a comet will hit earth in two years anyway, a court has heard.

A Supreme Court jury is deciding if James "Dimitrious" Gargasoulas is fit to enter a plea for allegedly mowing down pedestrians in January 2017, killing six and injuring dozens more.

Forensic psychiatrist Andrew Carroll testified that Gargasoulas told him on Tuesday he's "really not bothered" if he is jailed for as long as 23 years or sent for psychiatric treatment, because it'll be over in two years.

Gargasoulas believes he has lived seven times and in his last life, he only spent two years in prison before a "comet came and burned us all".

He believes the same will happen in mid-2020 or people will march on the Melbourne Assessment Prison and he will be released.

James Gargasoulas arrives in the prison van at the Melbourne Supreme Court. Picture: Nicole Garmston

Gargasoulas, 27, sat for much of the hearing with his head resting on his arms, face down.

At one point, Justice Mark Weinberg stopped to check he was awake, but was told he was just resting because his medication makes him tired.

Gargasoulas suffers treatment-resistant paranoid schizophrenia. Prof Carroll said Gargasoulas remains "very keen" to be found fit to stand trial because he wants his message about the comet believed.

He also understands a jury finding of mental impairment could affect how seriously he is taken.

"It's very important that someone takes me seriously, the comet and all that," he said Gargasoulas told him.

Prof Carroll says Gargasoulas also believed a mental impairment defence has "God written all over it" and he had pleaded that way because his lawyer, father and ex-partner advised him to.

"In my opinion, he is not able to rationally enter a plea," Prof Carroll told the court.

Crown prosecutor Kerri Judd QC has argued Gargasoulas is capable of rational thought and is making a bid to be held at Thomas Embling psychiatric hospital rather than jail, to enable his eventual release into the community.